A recent radio communication environment has been facing the problem of depletion of frequency resources due to a rapid increase in data traffic. Then, there has been an active discussion about a framework for releasing a frequency band given usage permission for a specific carrier but not used, for secondary communication. Such a frame work for the secondary communication is also called a licensed shared access (LSA). For example, European conference of postal and telecommunications administrations (CEPT) has proposed a technical requirement for devices that secondarily use a so-called “TV white space” not used for a television broadcasting (white space devices: WSDs) (see, for example, Non-Patent Literature 1 below).
Generally, transmission power of a transmitter secondarily using a frequency band is limited so as to prevent harmful interference to a receiver as a primary system. For example, in order to properly control the transmission power of the WSD, there has been proposed the installation of a geo-location database (GLDB) that provides information such as coverage, a position of a digital terrestrial television (DTT) receiver and an allowable interference level of a DTT system as a primary system (see, for example, Non-Patent Literature 1 below). Since the usage permission of the frequency band is normally given for each country (or region), the GLDB would be also installed for each country (or region). The GLDB can also perform such as a calculation of a protection ratio for protecting the primary system from the interference. A method for calculating the protection ratio has been presented (see, for example, Non-Patent Literature 2 below).
It has been proposed that an advanced geo-location engine (AGLE) for using the information provided from the GLDB to maximize a system capacity of a secondary system through a more advanced calculation is installed, for example, by a country or a third party (see, for example, Non-Patent Literature 3 below). It has been determined that the approach of installing the AGLE is adopted by an office of communications (OfCom) as a frequency management body in the UK, and a database developer as a third party.